The present invention generally relates to cooling devices, such as cooling chambers which utilize directly injected refrigerant to cool various products, such as biological samples.
In the past, a cooling chamber utilizing directly injected liquid nitrogen has been used to cool products such as biological samples. In one relevant prior device, liquid nitrogen is directly injected toward a cooling fan and then dispersed in both liquid and vapor form over the products within the chamber. Other types of liquid refrigerant may be utilized but, typically, liquid nitrogen is used and directly expands during this process into the air coming into contact with the product. Often, the expansion and vaporization of the refrigerant in a confined space, such as a chamber, is incomplete. This results in liquid refrigerant spraying on a portion of the product or products, causing rapid cooling of such portions of the product or products, while other portions of the product which are shielded from the liquid spray are cooled much more slowly. This non-uniform cooling is objectionable from a process standpoint.
To correct problems such as those mentioned above, it would be desirable to provide a rapid cooling device which, for example, more uniformly cools various items such as biological samples. This can ensure that the biological samples are frozen in a more viable state.